Hi, I currently have the AVH-X2800BS, but I might be getting the AVH-4100NEX from my brother in law for a low price.  I'm very excited about the prospect of dual USB + SD card for music storage, plus the other additional features.  The X2800BS is a decent unit, but there are a couple issues I'm wondering are present in the 4100:

 

After starting the car, it takes about 30 seconds before it will respond to any user input.  This is particularly annoying when I forget to turn down the volume before shutting off the car, because on startup it stays at the same volume, and if it's too loud, I have to sit there with it blaring loud for a while before it responds to my pressing the volume buttons.  The 10 year old Eclipse navigation unit it replaced did not suffer from this.

 

I have a 256GB USB @ FAT32 stick with a bit over 14,000 files and about 1,000 folders, mostly FLAC, but some MP3 and a few other compatible music formats.  No other files of any kind, just music and folders.  I have also used FAT Sorter to get the proper A-Z file reading.  Most tags have been removed, only track name and artist remain.  I strictly use file browser mode.  A couple issues: after letting the head unit create and save a database of the USB stick, every time I start the car, it takes over 2 minutes before it will play any music from the stick.  Also, scrolling down the among the files & folders is laggy, both in terms of the screen responding to my finger, and waiting for the folders to be displayed.

 

Any input, anyone?  I'm hoping the 4100 performs better at these issues than the much cheaper X2800BS.  I'm concerned that having both USBs and the SD slot jammed full of music will bring it to its knees.

 

Thanks!

I'm happy to report that after installing the AVH-4100NEX, it performs noticeably better than the AVH-X2800BS.  Thus far (I'm still compiling the music) I've tested it with 650GB comprising over 30,000 files (about 90% FLAC, otherwise MP3) spread over an SD card and two USB sticks, all of which are 256GB capacity and FAT32.  I'm going to continue pushing the capacity limits.  The touchscreen responds pretty much immediately upon full boot, unlike the 2800.  It also starts playback from the SD/SB inputs in about half the time.  It still takes about a minute before it will start playing music, which is still a lot longer than I'd like, but much improved over the 2800.  Hopefully in the future Pioneer or another maker will start using USB 3.0/3.1 inputs and upgrade the internal hardware to something more akin to a smartphone; my 3 1/2 year old Galaxy S4 has no lag loading up a 128GB of music on a MicroSD card, which the 4100 fails to do with the same card. However, I'm thrilled to have roughly 3,000 CDs on tap in my car with no physical media to mess with!

 

Moral of the story is that if budget is tight and you don't have more than 15K files to load up, the AVH-X2800BS is a decent head unit for a bit over $200.  But if you can swing the extra $ and have greater file usage needs, a NEX unit is worth it.  I've detected no difference in sound quality with my Rainbow 6.5" components & Butler tube amp + Alpine sub & Eclipse sub amp, but the snappier hardware and vastly increased inputs have made it a BIG upgrade to me, pushing me far closer to the dream of having every song I could want to hear on-hand at all times.